• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.12
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• pp.1120-1131
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• 2011

Researches using time reversal acoustics(TRA) for impact localization have been paid attention to recently. Dispersion characteristics of Lamb waves, which restrict the utility of classical nondestructive evaluation based on time-of-flight information, can be compensated through the application of TRA to Lamb waves on a plate. This study investigates the spatial focusing performance of time reversal Lamb waves on a plate using finite element analysis. In particular, the virtual sensor effect caused by multiple wave reflections at the boundaries of a plate is shown to enable the spatial focusing of Lamb waves though a very small number of surface-bonded piezoelectric(PZT) sensors are available. The time window size of forward response signals, are normalized with respect to the number of virtual active sensors. Then their effects on the spatial focusing performance of Lamb waves are investigated.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.418-429
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• 2011

Researches using time reversal acoustics (TRA) for impact localization have been paid attention to recently. Dispersion characteristics of Lamb waves, which restrict the utility of classical nondestructive evaluation based on time-of-flight information, can be compensated through the application of TRA to Lamb waves on a plate. This study investigates the spatial focusing performance of time reversal Lamb waves on a plate using finite element analysis. In particular, the virtual sensor effect caused by multiple wave reflections at the boundaries of the plate is shown to enable the spatial focusing of Lamb waves though a very small number of surface-bonded piezoelectric (PZT) sensors are available. The time window size of forward response signals, are normalized with respect to the number of virtual active sensors. Then their effects on the spatial focusing performance of Lamb waves are investigated.

• Journal of the Korean Society of Food Culture
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• v.19 no.4
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• pp.392-398
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• 2004

The purposes of this study were to: a) investigate how other countries brought up their traditional food into the commercial market for tourists b) analyze present marketing status of the Korean traditional food in dealing with foreign tourists as consumers. Present marketing status of the overseas and domestic tourism products focusing on traditional foods was investigated through literature reviews and face-to-face in-depth interviews conducted with professionals in tourism business. As a result, the foreign tourism products focusing on traditional foods were diverse and these products were representative of the regional heritage brought together in an effect to increase understanding of traditional foods. In case of the tourism products focusing on Korean traditional cuisine, the popular programs were 'Making Kimch', 'Making ricecake' and 'Making Bibimbap' in which tourists participated have expressed great satisfaction. The results of this study would be used as an important data in developing unique tourism programs focusing on Korean traditional cuisine attracting foreign tourists.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.41-46
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• 2021

This study, centered on mobile phone purchasers, verifies the effect of AR technology's convenience in consumer mobile shopping on consumers' intentions by focusing on the regulation effect of purchase satisfaction. According to the results of the hypothesis of SPSS, convenience has a positive (+) effect on both purchase intent and purchase satisfaction, and purchasing satisfaction plays a partial regulatory role between convenience and purchase intention. The results of this study are expected to provide users with various information using AR technology quickly and accurately in mobile shopping, thereby enhancing consumers' trust, providing pleasure, causing users to purchase intention, and realizing the untapped marketing effect more specifically.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.40-55
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• 2023

Currently, convenience stores, which are naturally located within a 1-minute walk, are easily accessible, so customers can easily purchase the items they need, and now they are indispensable places for people. In line with modern society that focuses on buying and selling goods quickly and easily, such as 'convenience' and 'quickness', convenience stores also have been changing by marketing such as home-delivery service and storage of fresh products, not just simply selling goods. In addition, by utilizing application software, we can use everything with one smartphone that we use a lot, in order to provide reservation delivery, pickup, and subscription services. In this study, we conducted experiments focusing on the factors of convenience store service quality and users using convenience stores, and examined how these experiments affect behavioral intentions of customers through their emotional responses. As a result, it was confirmed that empathy had a positive (+) effect on the pleasure of customers, and reliability had a negative (-) effect on arousal. In addition, it was found that empathy had a positive (+) effect on arousal, and responsiveness and empathy had a positive (+) effect on dominance. Finally, it was found that pleasure and dominance had a positive (+) effect on the loyalty of customers. In this study, we intend to provide basic data on existing or future convenience stores.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.122-123
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• 2002

능동적으로 안정화시킨 반도체 레이저의 빛살되먹임을 이용한 근접장 광학현미경(Near-field Scanning Optical Microscope)을 이용하여 칼코게나이드계 유리인 a-As$_2$S$_3$에서 광조사에 따른 자체집광 현상과 구조변화를 관찰하였다. 여러 비선형 광학현상 중 광 커르 효과(Optical Kerr effect)에 기인하는 자체집광(Self-focusing)은 광범위하게 연구되어 왔다. (중략)

• Journal of Energy Engineering
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• v.24 no.1
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• pp.78-87
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• 2015

Focusing effect of a metallic layer in a severe accident depending on the aspect ratios and cooling conditions of top plate and side wall was investigated. Experiments were carried out for Rayleigh numbers and aspect ratio in the range of $8.49{\times}10^7{\sim}5.43{\times}10^9$, 0.135~0.541 respectively. In order to achieve high Rayleigh numbers, the heat transfer experiments were replaced by mass transfer experiments based on the heat and mass transfer analogy. A sulfuric acid-copper sulfate ($H_2SO4-CuSO_4$) electroplating system was adopted as the mass transfer system. The experimental results agreed well with the Rayleigh-Benard natural convection correlations of Dropkin and Somerscales and Globe and Dropkin. When compared with the standard Rayleigh-Benard problem, the cooling by the side wall is even higher than the top. For a shorter height, the interaction between the heated and cooled plumes increases due to decrease of the height. Thus, the heat transfer increases.

• Journal of Industrial Convergence
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• v.13 no.2
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• pp.39-44
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• 2015

According to the result of this study, democracy, efficiency and consistency of governmental organizations gave the positive effect to public trust and private trust directly. But only democracy and efficiency affected to organizational commitment. As the analysis result of mediating effect, democracy and efficiency enhanced the total effect due to the mediating effect of public trust.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.715-722
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• 2012

A structural health monitoring (SHM) technique for locating impact position in a composite plate is presented in this paper. The technique employs a single sensor and spatial focusing properties of time reversal (TR) and inverse filtering (IF). We first examine the focusing effect of back-propagated signal at the impact position and its surroundings through simulation. Impact experiments are then carried out and the localization images are found using the TR and IF signal processing, respectively. Both techniques provide accurate impact location results. Compared to existing techniques for locating impact or acoustic emission source, the proposed methods have the benefits of using a single sensor and not requiring knowledge of material properties and geometry of structures. Furthermore, it does not depend on a particular mode of dispersive Lamb waves that is frequently used in the SHM of plate-like structures.

• Korean Journal of Child Studies
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• v.34 no.1
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• pp.87-102
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• 2013

This study examined the effects of paternal participation in child care and social support on planning for a second childbirth, focusing on the mediating effect of the mother's parenting stress. The 887 subjects studied in this paper were mothers who have a first child, and were selected from a sample of the 2nd Panel Study of Korean Children(PSKC) by the Korea Institute of Child Care and Education(KICCE), conducted in 2009. Data was analyzed using a Structural Equation Model(SEM) to identify a structure and relationships among factors. The significance of indirect effects to test the mediating effect of maternal parenting stress was identified via bootstrapping. Results indicated that maternal parenting stress partially mediated the relationship between the father's participation in child care and planning for a second childbirth, and absolutely mediated the relationship between social support and planning for a second childbirth. The findings reveal the importance of reducing parenting stress, given its substantial impact on planning for a second childbirth.